GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

Did you perform the Lighting Systems Diagnostic System Check?

--

Go to Step 2

Go to Diagnostic System Check - Lighting Systems

2

Disconnect the headlamp switch connector.

Do the park and tail lamps turn off?

--

Go to Step 6

Go to Step 3

3

Disconnect the dash integration module (DIM) connector C2.

Do the park and tail lamps turn off?

--

Go to Step 7

Go to Step 4

4

Disconnect the dash integration module (DIM) connector C1.

Do the park and tail lamps turn off?

--

Go to Step 9

Go to Step 10

5

Replace the rear fuse block. Refer to Rear Electrical Center or Junction Block Replacement in Wiring Systems.

Is the rear fuse block replacement complete?

--

Go to Step 12

--

6

Replace the headlamp switch. Refer to Headlamp Switch Replacement .

Is the headlamp switch replacement complete?

--

Go to Step 12

--

7

Repair the short to ground in CKT 301 (BRN/WHT). Refer to Wiring Repairs in Wiring Systems.

Is the circuit repair complete?

--

Go to Step 12

--

8

Replace the dash integration module (DIM). Refer to Dash Integration Module Replacement in Body Control System.

Is the DIM replacement complete?

--

Go to Step 12

--

9

Backprobe CKT 1080 (WHT) with a DMM from the DIM connector C1 cavity B5 (WHT) to ground.

Is the resistance less than the specified value?

0.5 ohms

Go to Step 11

Go to Step 8

10

Replace the PRK LP Relay.

Do the park and tail lamps turn off?

--

Go to Step 12

Go to Step 5

11

Repair the short to ground in CKT 1080 (WHT). Refer to Wiring Repairs in Wiring Systems.

Is the circuit repair complete?

--

Go to Step 12

--

12

Operate the system in order to verify the repair.

Did you correct the condition?

--

System OK.

Go to Step 2